I attended Roman Catholic Seminary throughout my high school years, as a willing and obedient believer in Church doctrine - every bit of it! But over the years, it has become plain to me that God is simply irrelevant to any question of acting morally: if you do right because you desire Heaven or fear Hell, you are not truly doing Right; you are merely economically efficient.
God is likewise unhelpful in figuring out moral questions. If you don't know enough not to steal, lie or kill, then you are a very foolish person indeed. And on the harder moral questions, God is unhelpfully vague.
But it is on the question of the afterlife that God still holds a promise: not that we will necessarily be rewarded or punished, but that we will not cease. Something in us fears The Great Dark, and no intellectual argument can still that fear. Along these lines, I enjoyed the following recent essay by Steven Weinberg
"The more we reflect on the pleasures of life, the more we miss the greatest consolation that used to be provided by religious belief: the promise that our lives will continue after death. As religious belief weakens, more and more of us know that after death there is nothing. Living without God isn't easy. But it offers an important consolation.digg story